Embodiments of this invention generally relate to driveshafts, and more particularly driveshafts for use in Ram Air Turbines (RATs).
RATs are commonly used on modern aircraft to provide a secondary or emergency power source in the event the primary power source is insufficient or fails. A typical RAT includes a turbine that remains internal to the aircraft until needed. When additional power is required, a door in the aircraft's fuselage will open deploying the RAT's turbine into the freestream air. The turbine is rotated by the freestream air and the rotational torque from the turbine is transferred through a drivetrain to be converted into electrical power by a generator. A RAT may also be used to drive a hydraulic pump. When deployed, the rotation of the RAT turbine creates centrifugal loading that causes torsional resonance, vibration and bending issues for the turbine, drivetrain and the generator.